To calculate your area in square meters, multiply the length by the width of the room. When ordering tiles, add an extra 10% for waste & cuts (15% if laying diagonally)
The proper preparation of the surface will make the fixing easier and quicker ensuring a better finish.
The surface should be flat with a tolerance of 4mm over a distance of 2 meters. It is essential that you waterproof wet areas prior to tiling.
New concrete is recommended to be 1 month old for every 25mm thickness and completely dried before tiling. It should also be a wood float finish, flat and free from dirt, dust and oils. Wooden floors must be rigid, stable and capable of the extra load without flexing.
Generally an underlay will be required to tile on wooden floors.
Expansion joints should be used as per Australian Standards 3956.1.
Source: Australian Tile Council website